Makes 1 (8-inch) cake
When my mom made a pineapple upside-down cake in a blue Pyrex pan, I thought we were eating the most exotic dessert, straight from Hawaii. I’m still pretty excited by it now.
Prepare to bake. Preheat the oven to 350°F.
Caramelize the pineapple. Set a 10-inch cast-iron skillet over medium heat. Add the coconut oil. When it has melted, add the coconut sugar and simmer, stirring, until the mixture turns a dark caramel color, about 4 minutes. Remove the skillet from the heat. Lay the pineapple slices on top of the caramel in concentric circles. Imperfect is best here.
(If you don’t have a cast-iron skillet, pour the caramel into a greased 8-inch cake pan and lay the pineapple slices over that.)
Combine the dry ingredients. In a large bowl, whisk together the flour blend, baking powder, baking soda, and salt. Set aside.
Cream the eggs and sugar. Add the eggs to the bowl of a stand mixer with the paddle attachment. Add the sugar and cream them together until they are light and fluffy. With the mixer running on low, pour in the melted coconut oil. Stop the mixer and scrape down the bowl with a rubber spatula.
Finish the batter. With the mixer running, add approximately one-third of the flour mixture to the cake batter. When the flour has disappeared into the batter, add half the sour cream. When the sour cream has blended in with the batter, stop the mixer and scrape down the sides of the bowl with a rubber spatula. Repeat, varying between the flour and sour cream, ending with the flour. The batter should be light and fluffy, sliding easily off the paddle. If the batter is too thick, add water, 1 tablespoon at a time with the mixer running on low, until the batter is pourable.
Bake the cake. Pour the batter evenly onto the pineapple in the skillet. Give it a little thump on the counter to settle the batter evenly. Put it on the middle rack in the oven. Bake until the cake has started to pull away from the edges of the pan and the center has a little athletic jiggle when you touch it, and a toothpick inserted into the center comes out clean, 20 to 30 minutes.
Cool the cake. Let the cake pan rest on the counter for 10 minutes. Gently, run a table knife around the edges of the cake. Put a plate over the skillet and turn the skillet upside down onto the plate. (Be sure to keep them firmly pressed together.) If there are any pineapple bits left in the skillet, put them onto the cake. Serve the cake warm.